In Schematic Design, the form and logic has to be settled. In Design Development, the pieces have to settle into shape, and the scale shifts from the global to the local. In Construction Documents, the scale devolves into individual components, and the building must come to life, from a simple line into a gyp wall, or an I-beam. In Construction Administration, you must build and coordinate the thing -- to respect the original intent of the first sketch.
Out of the blurry haze, and out of the muddy clay, something is emerging. And that something has its own internal logic and ambitions. It has a mind of its own. The task of the designer, and then the architect and manager, is to maintain the vision, and walk through the fog. In the fog, there are traps and obstacles -- roadblocks that prevent you from achieving your 20/20 vision. In most cases, the object at the end, when the dust settles -- is not what you have imagined. Actually, it may suck quite a bit. BUT it is the mere act of meditating - sometimes for decades - on this great thing you are to draw and build, that manifests into a habitable dwelling, with all its faults and ambitions, its wrongness and right, and all the things you've learned on the way, that makes the process worthwhile. And, hopefully, the next time you do it, you learned from your greatest mistakes.
And, when the building is completed, and the first inhabitants move in, it must feel effortless.